Synthesis Of Barium Titanate Nanotubes And Dielectric Properties Research Of Barium Titanate Nano-structure

Barium titanate(BaTi03, short BTO) is historically the first ceramic ferroelectric material. Due to the increased miniaturization and integration of ferroelectric components, much research in recent years has focused on nano-structures, One-dimensional (1D) nanostructure such as nanowires, nanorods and nanotubes have attracted a wide range of interests due to their structure dependent characteristics. This thesis contents two parts:one is the preparation of ferroelectric barium titanate nanotube array and it’s properties investigation; the second part analyzes the dielectric properties of nanocrystalline barium titanate, and focuses on the dielectric properties and relaxation mechanism of the70nm nanocrystalline barium titanate.A variety of TiO2nanotubes(TiNTs) were prepared with different voltage and time by anodic oxidation. Using X-ray diffraction (XRD) and scanning electron microscope (SEM) characterized the structure and microstructure of the sample.XRD spectrum showed the TiO2nanotubes prepared by anodic oxidation is amorphous type; SEM pictures prove that the sample has a highly ordered nanotube shape.After that, using the TiO2nanotube arrays as templates, taking the method of hydrothermal, consideration to the hydrothermal temperature, the hydrothermal time and the concentration of the hydrothermal solution, BaTiO3nanotube arrays were successfully prepared, meanwhile, XRD, SEM and Broadband Dielectric Spectrometer(BDS) were performed to test and character the samples. XRD data indicates that prepared BaTiO3nanotubes samples is a single cubic phase; SEM image show the sample has well-ordered tube structure, pipe wall became more thick than Ti02nanotube that before the hydrothermal response, a part of TiO2nanotube arrays has change into BaTiO3nanotube arrays; BDS test data show the dielectric constant of single crystal BaTiO3nanotube array film can be catch up to several hundred.Annealing treatment to the single crystal BaTiO3nanotube arrays, using different annealing temperature. Than using XRD, SEM, BDS and Ferroelectric analyzer(TF Analyzer) performed to test and character the samples. XRD data indicates after annealing treatment, the tetragonal and cubic phase mixture structure could be obtained; SEM image shows the shape of the nanotubes could be stabilized even at the temperature high to800℃; BDS test data shows BaTiO3nanotube arrays film dielectric constant increases significantly after annealing treatment close to1000; TF Analyzer has measured the electric hysteresis loop of the sample, that means after annealing ferroelectric BaTiO3nanotube arrays film is obtained. At last, the dielectric behaviors of nanocrystalline BaTiO3ceramics were investigated. The relations between the grain size and phase transformation has been studied; the Discusses the relaxation mechanism of70nm BaTiO3, and attributed the large dielectric constant at low frequency to Maxwell-Wagner effect; found that the nanocrystalline barium titanate has thermal activation effect, it is accord to Debye relaxation model within a certain range, at low frequency it deviates from the Debye model is coursed by the interfacial polarization...